Phosphate, calcium, and vitamin D signaling, transport, and metabolism in the endometria of cyclic ewes

Abstract

Background Recent evidence suggests important roles for progesterone (P4) and interferon tau in the regulation of calcium, phosphate, and vitamin D signaling in the uteri of pregnant sheep. However, the effects of P4 and estradiol (E2), with respect to the expression of their receptors PGR and ESR1, respectively, in uterine epithelia on mineral signaling during the estrous cycle has not been investigated. Estrous cycles of mature Suffolk ewes were synchronized, prostaglandin F2α was administered, and ewes were observed for estrus (designated as Day 0) in the presence of vasectomized rams. On Days 1, 9, or 14 of the estrous cycle, hysterectomies were performed. Results 25-hydroxyvitamin D was more abundant in plasma from ewes on Day 14 than Day 1 (P < 0.05). Expression of fibroblast growth factor receptor 2 (FGFR2), a disintegrin and metalloprotease 17 (ADAM17), and parathyroid hormone-related protein (PTHrP) mRNAs was greater in endometria on Day 9 compared to Days 1 and 14 (P < 0.01). Similarly, expression of transient receptor potential cation channel subfamily V member 6 (TRPV6) mRNA was greater in endometria on Day 9 than Day 1 (P < 0.05). ATPase plasma membrane Ca2+ transporting 4 (ATP2B4) and S100 calcium binding protein G (S100G) mRNA expression was greater in endometria on Day 14 than on Days 1 and 9 (P < 0.01). In contrast, endometrial expression of vitamin D receptor (VDR) mRNA was lower on Days 9 and 14 than Day 1 (P < 0.01). Expression of klotho (KL) (P < 0.05) and cytochrome P450 family 24 subfamily A member 1 (CYP24) (P < 0.01) mRNAs was lower on Day 14 than Days 1 and 9. ADAM17, FGF23, CYP2R1, CYP27B1, KL, and VDR proteins immunolocalized to the uterine myometrium, blood vessels, and uterine luminal (LE), superficial glandular (sGE), and glandular (GE) epithelia. S100A9 protein was weakly expressed in the uterine myometrium, LE, sGE, and GE. Immunoreactivity of CYP2R1 and KL proteins in uterine LE and sGE was less on Day 1 than on Days 9 and 14. In contrast, S100G protein was expressed exclusively by GE, and immunoreactive S100G protein was less on Day 9. S100A12 protein localized to stromal cells of the uterine stratum spongiosum and blood vessels, but not by uterine epithelial cells. Conclusion Collectively, these results implicate E2, P4, and PGR in the regulation of phosphate, calcium, and vitamin D signaling in cyclic ewes.

Characterization of TNSALP expression, localization, and activity in ovine utero-placental tissues

“…Stages in which expression was examined are: (1) Day 1 (early metestrus) characterized by decreasing concentrations of E2 and low concentrations of P4 in maternal plasma, and expression of both ESR1 and PGR in uterine epithelia; (2) Day 9 (early diestrus) characterized by low concentrations of E2 and high concentrations of P4 in maternal plasma with the downregulation of ESR1 and upregulation of PGR in uterine epithelia; and (3) Day 14 (late diestrus) characterized by very low concentrations of E2, high concentrations of P4 in maternal plasma, and the decreased expression of both ESR1 and PGR in uterine epithelial cells [27–29]. Results of this study revealed no effect of Day of the estrous cycle on expression of ALPL mRNA which is consistent with a lack of an effect of Day of the estrous cycle on the abundance of phosphate in uterine f lushings in sheep [32–34]. However, there tended to be lower endometrial expression of ALPL mRNA on Day 9, suggesting that increasing concentrations of P4 in plasma, which can bind to PGR in uterine LE and sGE, is associated with decreased endometrial expression of ALPL mRNA.…”

Progesterone regulates tissue non-specific alkaline phosphatase (TNSALP) expression and activity in ovine utero-placental tissues

“…On Day 12 of gestation, endometria from P4 treated ewes had greater expression of ALPL mRNA, which was accompanied by an apparent increase in TNSALP activity in epithelia, stratum compactum stroma, and endothelial cells of blood vessels in the endometrium and myometrium. We have recently reported greater TNSALP activity in the endometrial stratum compactum stroma of Day 14 cycle ewes compared to that for endometria from Day 1 or Day 9 of the estrous cycle [ 32 ]. Thus, it could be speculated that following PGR downregulation in the endometrial LE and sGE, P4 not only alters TNSALP to alter phosphate availability in epithelia, but also regulates TNSALP activity in the endometrial stratum compactum stroma, which could alter phosphate availability.…”

Regulation of synthesis of polyamines by progesterone, estradiol, and their receptors in uteri of cyclic ewes

“…The stability of reference genes was assessed by geNORM V3.5 (Ghent University Hospital, Centre for Medical Genetics, Ghent, Belgium) with an M value of < 1.5. The reference genes tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (% YWHAZ ) and beta-2-microglobulin ( B2M ) were determined to have stable expression across days of the estrous cycle [18]. Additionally, effects of day of the estrous cycle were determined using JMP to ensure that there was no effect of day on the expression of the reference genes ( P> 0.1).…”